Despite appearances, Emmons is not the diet police. She’s more of an accidental inspector of artery-clogging trans fats, which come from the partial hydrogenation of vegetable oil and can be found in foods such as margarine, icing, cookies, potato chips, and certain fried foods. Trans fats have been directly linked to heart disease, obesity, and increasing levels of so-called “bad’’ cholesterol.

“The real reason people use trans fats in these baked goods is the shelf life, pliability, and the mouth-feel is better - there’s nothing like it, except for butter or lard,’’ Emmons said. “If it wasn’t bad for you, it would be great because it has everything else over any kind of fat. . . . It’s like finding the most agreeable person you’ve ever met, and then being told that that person is bad for you. It just doesn’t make sense.’’

Emmons, 49, has quickly become the go-to consultant for health officials in communities looking to implement bans on trans-fatty acids in food-serving establishments, including in Chelsea and Lynn, where bans took effect Jan. 1.

She was first selected by the Boston Public Health Commission to help chefs, bakers, and cooks seek alternatives to ingredients with trans fats, or alter their recipes after the city adopted a ban in 2008. It was Emmons’s background as a natural foods chef and her work at the nonprofit soup kitchen and community bakery Haley House in Roxbury that made her the ideal candidate for the Boston consulting job, said Gerry Thomas, director of the commission’s Community Initiatives Bureau.

“She had the background of the restaurant work, and a strong nutritional background,’’ Thomas said.

In 2010, the commission partnered with Lynn’s Public Health Division after being awarded a Centers for Disease Control and Prevention grant that required Boston to allocate 10 percent of the funds toward mentoring other communities working on disease-prevention programs, Thomas said. Lynn received $20,000 from the grant, which was given to various health initiatives, including the trans-fat ban, and was used to hire Emmons as a consultant, said MaryAnn O’Connor, director of Lynn’s Public Health Division.

Emmons has been making the rounds at eateries in Lynn, scrutinizing portion sizes, oils, bags of baking mixes, shortening, and myriad icings and fillings, and she suggests alternatives. Torretta, who opened D’Amici’s in 1993 after a career in engineering, told Emmons during her recent visit that the lemon filling he uses is actually free of trans fats. Like Torretta, many cooks, chefs, and bakers in Lynn and Chelsea have discovered that they were already using ingredients free of trans fats, Emmons said. And those who are not are open to the changes, she added.

Places like D’Amici’s and Donut City in Lynn, which she also visited on the same afternoon last month, are examples of bakeries whose owners were quick to implement the changes, Emmons said. But it hasn’t been easy, said Donut City owner Chann Kim. Area restaurant warehouses often receive ingredients from the same distributor, making it harder to find trans-frat-free varieties, he said. At times, the trans-fat-free versions are also more expensive. Kim said he is paying about $12 more a week for a zero-trans-fat shortening for frying doughnuts, but he is leery of raising his prices out of fear of losing customers.

The Boston Public Health Commission also recommended Emmons to Chelsea to help with its ban on trans fats. Using part of a $75,000 CDC grant awarded to the city in 2010, Massachusetts General Hospital’s Chelsea HealthCare Center worked with Emmons to create a trans-fat enforcement checklist to be used by the city’s health inspectors, said Melissa Dimond, manager of community initiatives at the health center.

“She was able to do the research and have a relationship with bakers because she was hired to do this for Boston, and she developed an expertise that no one else has,’’ Dimond said. “It’s true that she’s better known for her work related to organic cooking, but she’s clearly good at this.’’

Her background is why Emmons, who lives in Jamaica Plain, said she was “an unlikely choice’’ for the job, given that she had never worked in mid-level bakeries that relied on premixed ingredients.

“It’s a completely different set of skills I had to learn, a type of baking I’d never learned before, from mixes, and bags, and frostings,’’ Emmons said. “And it’s given me a new respect for people who do the work there, because so much passion goes into it.’’

A French-trained chef, Emmons began her professional career at fine-dining establishments and high-end bakeries in New York and Boston. She inherited her passion for quality food from her father - a man with a discerning palate - and her mother, whose mission it was to please her family’s tastes with the best food available.

“I think we paid a lot of attention to food, both my parents did,’’ Emmons said. “When I was in sixth or seventh grade, I took a home economics class and they taught me to make applesauce, and I went home and made it and thought, ‘Oh my God, I can’t believe nobody goes home and does this. It’s so much better than Mott’s.’ I remember it smelled so great.’’

By 14, Emmons and a friend had started their own catering service, and were hired for more than a dozen parties. At 16, she started a job at a “very fancy’’ cheese shop, where she worked for the next four years and learned much more about quality food. She went on to attend New York University, where she majored in food service management, and by 27 she was an apprentice for a chef in France.

“I think for me it was kind of inevitable,’’ Emmons said. “I felt a sense of love for food. I didn’t quite have that passion for anything else.’’

She returned to New York, where she worked as a pastry chef, and then moved to Boston, where she worked at a high-end South End bistro. Over the next 15 years, Emmons became the founding chef of four restaurants, including Haley House and Veggie Planet in Harvard Square. She has also written three books, including the recently published “Wild Flavors.’’

It was at Haley House where Emmons said she got a new education - working with low-income residents who have little access to better-quality food. It is also why she said she enjoys the consulting jobs in Chelsea and Lynn.

“These cities that have low-income populations, people have no idea what they’re eating, and it’s a total public service to them,’’ she said. “I love working with kids, but I had no idea that there was just one more thing, one more strike against them in this world. I had to become an activist about it; become very vigilant in teaching the kids that it’s not just about having fun cooking food, but knowing what whole foods are, and eating whole foods.’’